The invention relates to a valve for an aerosol can. The valve is of the type for spraying a product contained under gas pressure in the can and has a body fixed to the can and projecting towards the interior of this can. An actuating rod is accessible from the exterior of the can and adapted to be displaced by the action of the user in order to open the valve.
When spraying a product, especially hair lacquer, it is desirable to obtain high quality spraying over the entire period of use of the can, i.e. a suitable flow rate and size of the atomised droplets. This problem arises in particular when the gas pressure in the interior of the can is ensured by means of a compressed gas (N.sub.2, CO.sub.2 or air), because the pressure gradually decreases during repeated use.